in a jam: You are jammed up (1940s+)
The screen was still blank, indicating that the jammer was sweeping in frequency.
He was almost upon the fragment shielding him from the jammer.
If that fails, they send a jammer impulse and freeze it up tight.
He would have to look on the other side of the jammer, using the ship itself as a shield.
He next tried to synchronize his radar pulses with the jammer, in order to be looking when it was quiet.
The image of the jammer started to expand as he approached it.
He switched off the radar, and aimed the ship slightly to one side of the infrared image of the jammer.
He found that the enemy had anticipated him again, and the jammer's signal strength varied.
However, he finally stopped the antenna, satisfied that he had it pointed at the jammer.
He started the fuel pumps winding up, and swung the ship to point normal to the line-of-sight to the jammer.